Natalya Lvoff MD, Presenter: Nothing to Disclose

Jessica Wai Ting Leung MD, Abstract Co-Author: Nothing to Disclose

Edward A. Sickles MD, Abstract Co-Author: Nothing to Disclose

R. James Brenner MD, JD, Abstract Co-Author: Reviewer, Allergan, Inc

To review the clinical and pathological outcomes for cases of single dilated duct identified at mammography.

This is a retrospective review of all screening and diagnostic mammography examinations performed at a single institution during a 20-year period. At the time of interpretation, the principal finding of each abnormal mammographic examination was recorded in a database. All such examinations with the recorded finding of single dilated duct (without associated mass or calcifications) were included in the study. We examined radiology records to determine imaging follow-up, pathology records to determine histological diagnosis, and performed linkage with our regional tumor registry to identify any cancers not biopsied at our own institution.

The finding of single dilated duct was recorded for 9 of 200,732 consecutive screening mammography examinations (0.0045%) and for 12 of 34,477 consecutive diagnostic mammography examinations (0.035%). Five of the screening and 5 of the diagnostic cases were stable at follow-up (minimum interval, 2 years) and did not undergo biopsy. Tumor registry linkage showed no subsequent cancer diagnosis for any of these cases. Biopsy was performed for 4 of 9 screening (44%) and 7 of 12 diagnostic (58%) cases. One cancer each (ductal carcinoma in situ) was identified from the screening and diagnostic populations, yielding positive predictive values of 1/9 (11%) and 1/12 (8%), respectively.

Single dilated duct is a rare mammographic finding, this series being the largest reported to date. Although few cases are studied, single dilated duct appears to have a greater than 2% likelihood of malignancy, sufficiently high to suggest that a suspicious (BI-RADS 4A) assessment may be more appropriate than the previously-proposed probably benign (BI-RADS 3) assessment.

The frequency of breast cancer in patients with a single dilated duct identified at mammography may be sufficiently high to warrant a suspicious rather than a probably benign assessment.

Lvoff, N, Leung, J, Sickles, E, Brenner, R, The Single Dilated Duct Identified at Mammography: Outcomes Analysis.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5008161.html